packages/mcp stays free of prom-client/server: it only calls an optional
DocmostMcpConfig.onMetric(name, value, labels?) sink the host provides.
- client.ts: onMetric on the config; fires collab_connect_timeouts_total
once, only inside the 25s connect-timeout callback (the connect-vs-unload
signal). cleanup() clears the timer on every other finish path, so no
double-count.
- index.ts: createDocmostMcpServer monkeypatches server.registerTool (before
registerShared + inline tools are registered) to wrap every handler with
timeToolHandler — times in a finally on success AND throw, re-throws
unchanged, emits mcp_tool_duration_seconds{tool=<registered name>} (bounded
cardinality). Single choke point catches all tools.
- mcp.service.ts: the per-request config resolver injects onMetric ONLY when
isMetricsEnabled(), routing mcp_tool_duration_seconds -> observeMcpTool and
collab_connect_timeouts_total -> incConnectTimeout. Disabled / standalone
(stdio, no onMetric) -> undefined -> zero-overhead no-op.
New node:test unit (tool-timing.test.mjs) covers the wrapper's value/throw
preservation and the standalone no-op. packages/mcp/build/ is gitignored,
not committed (CI rebuilds it).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
agent_coder
7a9d719877